|   | 
Details
   web
Records
Author Batuk, M.; Buffiere, M.; Zaghi, A.E.; Lenaers, N.; Verbist, C.; Khelifi, S.; Vleugels, J.; Meuris, M.; Hadermann, J.
Title Effect of the burn-out step on the microstructure of the solution-processed Cu(In,Ga)Se2 solar cells Type A1 Journal article
Year (down) 2015 Publication Thin solid films : an international journal on the science and technology of thin and thick films Abbreviated Journal Thin Solid Films
Volume 583 Issue 583 Pages 142-150
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract For the development of the photovoltaic industry cheap methods for the synthesis of Cu(In,Ga)Se-2 (CIGSe) based solar cells are required. In this work, CIGSe thin films were obtained by a solution-based method using oxygen-bearing derivatives. With the aimof improving the morphology of the printed CIGSe layers, we investigated two different annealing conditions of the precursor layer, consisting of (1) a direct selenization step (reference process), and (2) a pre-treatment thermal step prior to the selenization. We showed that the use of an Air/H2S burn-out step prior to the selenization step increases the CIGSe grain size and reduces the carbon content. However, it leads to the reduction of the solar cell efficiency from 4.5% in the reference sample down to 0.5% in the annealed sample. Detailed transmission electron microscopy analysis, including high angle annular dark field scanning transmission electron microscopy and energy dispersive X-ray mapping, was applied to characterize the microstructure of the film and to determine the relationship between microstructure and the solar cell performance. We demonstrated that the relatively low efficiency of the reference solar cells is related not only to the nanosize of the CIGSe grains and presence of the pores in the CIGSe layer, but also to the high amount of secondary phases, namely, In/Ga oxide (or hydroxide) amorphous matter, residuals of organicmatter (carbon), and copper sulfide that is formed at the CIGSe/MoSe2 interface. The annealing in H2S during the burn-out step leads to the formation of the copper sulfide at all grain boundaries and surfaces in the CIGSe layer, which results in the noticeably efficiency drop. (C) 2015 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Lausanne Editor
Language Wos 000353812400024 Publication Date 2015-04-05
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0040-6090; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.879 Times cited 5 Open Access
Notes Approved Most recent IF: 1.879; 2015 IF: 1.759
Call Number c:irua:126009 Serial 845
Permanent link to this record
 

 
Author Brammertz, G.; Buffiere, M.; Verbist, C.; Bekaert, J.; Batuk, M.; Hadermann, J.; et al.
Title Process variability in Cu2ZnSnSe4 solar cell devices: Electrical and structural investigations Type P1 Proceeding
Year (down) 2015 Publication The conference record of the IEEE Photovoltaic Specialists Conference T2 – IEEE 42nd Photovoltaic Specialist Conference (PVSC), JUN 14-19, 2015, New Orleans, LA Abbreviated Journal
Volume Issue Pages
Keywords P1 Proceeding; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract We have fabricated 9.7% efficient Cu2ZnSnSe4/CdS/ZnO solar cells by H2Se selenization of sequentially sputtered metal layers. Despite the good efficiency obtained, process control appears to be difficult. In the present contribution we compare the electrical and physical properties of two devices with nominal same fabrication procedure, but 1% and 9.7% power conversion efficiency respectively. We identify the problem of the lower performing device to be the segregation of ZnSe phases at the backside of the sample. This ZnSe seems to be the reason for the strong bias dependent photocurrent observed in the lower performing devices, as it adds a potential barrier for carrier collection. The reason for the different behavior of the two nominally same devices is not fully understood, but speculated to be related to sputtering variability.
Address
Corporate Author Thesis
Publisher Ieee Place of Publication New york Editor
Language Wos Publication Date
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-1-4799-7944-8 ISBN Additional Links UA library record; WoS full record
Impact Factor Times cited Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:132335 Serial 4229
Permanent link to this record
 

 
Author Buffière, M.; Brammertz, G.; Batuk, M.; Verbist, C.; Mangin, D.; Koble, C.; Hadermann, J.; Meuris, M.; Poortmans, J.
Title Microstructural analysis of 9.7% efficient Cu2ZnSnSe4 thin film solar cells Type A1 Journal article
Year (down) 2014 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 105 Issue 18 Pages 183903
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract This work presents a detailed analysis of the microstructure and the composition of our record Cu 2ZnSnSe4 (CZTSe)-CdS-ZnO solar cell with a total area efficiency of 9.7%. The average composition of the CZTSe crystallites is Cu 1.94 Zn 1.12Sn0.95Se3.99. Large crystals of ZnSe secondary phase (up to 400 nm diameter) are observed at the voids between the absorber and the back contact, while smaller ZnSe domains are segregated at the grain boundaries and close to the surface of the CZTSe grains. An underlying layer and some particles of Cu xSe are observed at the Mo-MoSe2-Cu2ZnSnSe4 interface. The free surface of the voids at the back interface is covered by an amorphous layer containing Cu, S, O, and C, while the presence of Cd, Na, and K is also observed in this region.
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000345000000086 Publication Date 2014-11-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951;1077-3118; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 17 Open Access
Notes Approved Most recent IF: 3.411; 2014 IF: 3.302
Call Number UA @ lucian @ c:irua:121329 Serial 2038
Permanent link to this record
 

 
Author E. Zaghi, A.; Buffière, M.; Koo, J.; Brammertz, G.; Batuk, M.; Verbist, C.; Hadermann, J.; Kim, W.K.; Meuris, M.; Poortmans, J.; Vleugels, J.;
Title Effect of selenium content of CuInSex alloy nanopowder precursors on recrystallization of printed CuInSe2 absorber layers during selenization heat treatment Type A1 Journal article
Year (down) 2014 Publication Thin solid films : an international journal on the science and technology of thin and thick films Abbreviated Journal Thin Solid Films
Volume Issue Pages 1-7
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Polycrystalline CuInSe2 semiconductors are efficient light absorber materials for thin film solar cell technology, whereas printing is one of the promising low cost and non-vacuum approaches for the fabrication of thin film solar cells. The printed precursors are transformed into a dense polycrystalline CuInSe2 semiconductor film via thermal treatment in ambient selenium atmosphere (selenization). In this study, the effect of the selenium content in high purity mechanically synthesized CuInSex (x = 2, 1.5, 1 or 0.5) alloy precursors on the recrystallization of the CuInSe2 phase during the selenization process was investigated. The nanostructure and phase variation of CuInSex nanopowders were investigated by different characterization techniques. The recrystallization process of the 12 μm thick CuInSex coatings into the CuInSe2 phase during selenization in selenium vapor was investigated via in-situ high temperature X-ray diffraction. The CuInSex precursors with lower selenium content showed a more pronounced phase conversion into CuInSe2 compared to the higher selenium content CuInSex precursors. Moreover, the CuInSex (x = 0.5 and 1) precursor resulted in a denser polycrystalline CuInSe2 semiconductor film with larger crystals. This could be attributed to a more intensive atomic interdiffusion within the CuInSex precursor system compared to a CuInSe2 phase precursor, and the formation of intermediate CuSe and CuSe2 fluxing phases during selenization.
Address
Corporate Author Thesis
Publisher Place of Publication Lausanne Editor
Language Wos 000352225900004 Publication Date 2014-10-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0040-6090; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.879 Times cited 7 Open Access
Notes Approved Most recent IF: 1.879; 2014 IF: 1.759
Call Number c:irua:121330 Serial 834
Permanent link to this record